Sandford was born in London and brought up at Eye Manor in Herefordshire, home of his father, Christopher Sandford, who was the owner of the Golden Cockerel Press. His mother was Lettice Sandford. Sandford went to school at Eton and then went to Oxford University. He married heiress Nell Dunn in 1957. They gave up their smart Chelsea home and went to live in unfashionable Battersea where they joined and observed the lower strata of society, and from this experience he published the play Cathy Come Home in 1963, and his wife, Nell, wrote Up the Junction.

In 1968, Sandford won a Jacob's Award for the TV production of Cathy Come Home.

Sandford became interested in gypsy causes and for a time edited their news sheet, Romano Drom (Gypsy Road). He travelled the country seeking out gypsy stories, published as The Gypsies, and later reissued as Rokkering to the Gorjios (Talking to the non-Gypsies).

Jeremy Sandford and his wife Nell Dunn were divorced in 1979 after having had three sons together.

He died at his home, Hatfield Court in Herefordshire, at the age of seventy-two. His last words were "I think I'll have a rest now."